1. Field of the Invention
The present invention relates to an autonomic nerve regulating agent having sedative action, sleep improving action, stress mitigation action, and the like.
2. Discussion of the Related Art
When the balance between the activities of the parasympathetic nervous system and the sympathetic nervous system is upset by physical and mental stress, the resulting disequilibrium in the autonomic nervous system can lead to mental aggravation, making it difficult to fall asleep very easily (sleep induction) and resulting in shallow sleep. It is believed that stimulating the physiological predominance of the parasympathetic activity over the sympathetic activity can reduce stress and calm aggravated mental states, thus inducing favorable sleep.
Methods that have long been used to thus stimulate the predominance of the parasympathetic activity over the sympathetic activity include the oral or percutaneous administration of active ingredients to humans, as well as aromatherapy involving vaporizable fragrance compositions to allow the vapors to be inhaled. Recent proposals include methods in which bitter orange essential oil (Japanese Laid-Open Patent Application Kokai) H4-128234) and jasmine lactone (Japanese Laid-Open Patent Application (Kokai) H6-40911) are administered by absorption via the nasal mucosa, oral mucosa, or pulmonary tissue for better sleep induction.
The use of the low-boiling components of cedar wood oil (such as α-pinene, α-cedrene, β-cedrene, and caryophyllene) as a sedative essential oil has also been proposed (Japanese Laid-Open Patent Application (Kokai) H5-255688).
It is not altogether clear-whether or not the effects of such fragrances or essential oil components are determined solely by their action on the autonomic nervous system, and it has been assumed that action mediated by other physiological routes, including the lower central nervous system, may be involved.
There is substantial individual variation in the sensitivity to and preference for scents (fragrances) such as bitter orange essential oil and jasmine lactone. While these may have sedative and sleep inducing action for some people, they may on the contrary be disagreeable or irritating to others. There is thus a need for a component or method capable of universally improving autonomic nervous imbalances (in other words, restoring the balance to a physiologically ideal state) whose effects are not biased by odor perceptions.
The low-boiling components of cedar wood oil have a strongly characteristic fragrance, and their sedative actions are also subject to considerable individual variation in terms of people's sensitivity and preferences in the same manner as bitter orange essential oil and the like.